An optical transponder aggregator is a flexible optical network element for carrying traffic onto and off an optical network. Each transmitter Tx or receiver Rx in a transponder aggregator can connect to any one of a plurality of wavelengths, and the transponder aggregator includes photonic switches implementing selections of different wavelengths and setting the connection pattern. A transponder aggregator typically includes two optical waveguide modules, a drop switch module and an add switch module.
To minimize costs and chip sizes, the switch modules can be implemented as photonic integrated circuits (PIC), typically silicon photonics. Due to the number of channels existing in the entire optical band and the size of the PIC chip, existing PIC chips do not have broad band operating capability and current solutions involve implementing different sub-bands on different chips. As well, in many applications it is desirable to separate the drop switch module and add switch module into different chips, due to yield or chip size limitations, or because operators prefer to assemble the networks using separate add switch and drop switch. These are all factors that contribute to circuit, manufacturing and packaging complexity.
Accordingly, while transponder aggregators offer great operational flexibility, there is a need to simplify photonic chip designs for manufacturing and to bring down the costs for market implementations.